diff --git a/src/py/bbctrl/AuxAxis.py b/src/py/bbctrl/AuxAxis.py
index 7ff1a4b..bbcc7bf 100644
--- a/src/py/bbctrl/AuxAxis.py
+++ b/src/py/bbctrl/AuxAxis.py
@@ -230,6 +230,55 @@ class AuxAxis(object):
         except Exception as e:
             self.log.warning('ABORT send failed: %s' % e)
 
+    # ---------------------------------------------------------- ATC commands
+    #
+    # The auxcnc firmware drives an AMB 1050 FME-W DI tool changer via
+    # three pneumatic valves on relays 1-3. The ESP runs the timed
+    # sequences itself; the host just kicks them off and waits for the
+    # terminal reply.
+
+    def atc_droptool(self, timeout=30.0):
+        """Eject the current tool. Opens the collet (V1), oscillates the
+        ejector (V2), then re-clamps with a bleed cycle. Blocks until
+        the ESP reports done. Raises on failure."""
+        self._require_present()
+        line = self._rpc('DROPTOOL', topic='droptool', timeout=timeout)
+        if line.startswith('done'):
+            return
+        reason = line.split('reason=', 1)[1] if 'reason=' in line else line
+        raise AuxAxisError('DROPTOOL failed: %s' % reason)
+
+    def atc_grabtool(self, timeout=30.0):
+        """Pick up a tool that's already been seated by the operator.
+        Opens V1 (releases the collet), waits for the operator to insert
+        the holder, then re-clamps with a bleed cycle. Blocks."""
+        self._require_present()
+        line = self._rpc('GRABTOOL', topic='grabtool', timeout=timeout)
+        if line.startswith('done'):
+            return
+        reason = line.split('reason=', 1)[1] if 'reason=' in line else line
+        raise AuxAxisError('GRABTOOL failed: %s' % reason)
+
+    def atc_release(self, timeout=5.0):
+        """Manually open the collet (release-only, no clamp). Use
+        atc_clamp() afterwards once the new holder is in place."""
+        self._require_present()
+        line = self._rpc('RELEASE', topic='release', timeout=timeout)
+        if line.startswith('done'):
+            return
+        reason = line.split('reason=', 1)[1] if 'reason=' in line else line
+        raise AuxAxisError('RELEASE failed: %s' % reason)
+
+    def atc_clamp(self, timeout=10.0):
+        """Manually clamp the collet (run a full bleed cycle). Pairs
+        with atc_release() for two-step manual tool changes."""
+        self._require_present()
+        line = self._rpc('CLAMP', topic='clamp', timeout=timeout)
+        if line.startswith('done'):
+            return
+        reason = line.split('reason=', 1)[1] if 'reason=' in line else line
+        raise AuxAxisError('CLAMP failed: %s' % reason)
+
     def close(self):
         self._stop.set()
         try:
diff --git a/src/py/bbctrl/Ctrl.py b/src/py/bbctrl/Ctrl.py
index ede7c52..b2d8862 100644
--- a/src/py/bbctrl/Ctrl.py
+++ b/src/py/bbctrl/Ctrl.py
@@ -156,6 +156,11 @@ class Ctrl(object):
             mm = float(data) if data else 0.0
             self.aux.set_position_mm(mm)
 
+        def _hook_droptool(ctx):  self.aux.atc_droptool()
+        def _hook_grabtool(ctx):  self.aux.atc_grabtool()
+        def _hook_release(ctx):   self.aux.atc_release()
+        def _hook_clamp(ctx):     self.aux.atc_clamp()
+
         self.hooks.register_internal('aux',         _hook_move,
                                      block_unpause=True, auto_resume=True)
         self.hooks.register_internal('aux_rel',     _hook_move_rel,
@@ -165,6 +170,21 @@ class Ctrl(object):
                                      timeout=180)
         self.hooks.register_internal('aux_setzero', _hook_setzero,
                                      block_unpause=True, auto_resume=True)
+        # ATC pneumatics. block_unpause + auto_resume so a program
+        # using M6 - implemented as (MSG,HOOK:droptool:) etc - pauses
+        # at the right point and resumes once the sequence is done.
+        self.hooks.register_internal('droptool',    _hook_droptool,
+                                     block_unpause=True, auto_resume=True,
+                                     timeout=60)
+        self.hooks.register_internal('grabtool',    _hook_grabtool,
+                                     block_unpause=True, auto_resume=True,
+                                     timeout=60)
+        self.hooks.register_internal('release',     _hook_release,
+                                     block_unpause=True, auto_resume=True,
+                                     timeout=10)
+        self.hooks.register_internal('clamp',       _hook_clamp,
+                                     block_unpause=True, auto_resume=True,
+                                     timeout=15)
         log.info('Aux hooks registered')